topic Re: extract une substring inside a string with separator in SAS Programming

extract une substring inside a string with separator

Nasser_DRMCP — Fri, 05 Jun 2020 15:30:04 GMT

Hello,

I get pathnames in a macro variable and I would like to extract the string between the 4th folder and the program name

exemple1, '/data/crea/creapil/sbsas/SUIVIS/ACCEPTATION/SUI_Q_DOS_PAI.sas' the result should be /SUIVIS/ACCEPTATION/

example 2 '/data/crea/creapil/sbsas/SUIVIS/CLIENT/RECOUV/CESSION/SUI_Q_CESSION.sas' the result should be SUIVIS/CLIENT/RECOUV/CESSION/

thanks in advance for your help

regards

Nas

Re: extract une substring inside a string with separator

novinosrin — Fri, 05 Jun 2020 15:44:25 GMT

Hi @Nasser_DRMCP What you need is CALL SCAN

data have;
length str $200;
str= '/data/crea/creapil/sbsas/SUIVIS/ACCEPTATION/SUI_Q_DOS_PAI.sas' ;
output;
str='/data/crea/creapil/sbsas/SUIVIS/CLIENT/RECOUV/CESSION/SUI_Q_CESSION.sas';
output;
run;

data want;
 set have;
 call scan(str, 5, _p, _l,'/');
 call scan(str, -1, _p1, _l1,'/');
 need=substr(str,_p-1,_p1+1-_p);
 drop _:;
run;

Re: extract une substring inside a string with separator

Nasser_DRMCP — Fri, 05 Jun 2020 15:55:05 GMT

thanks for your quick respons.
could you please explain call scan(str, 5, _p, _l,'/'); ?

Re: extract une substring inside a string with separator

smantha — Fri, 05 Jun 2020 15:56:12 GMT

Novin's solution is good as long as you know what position to start the data from. I learnt something new today. Call Scan function, did not use it.

Re: extract une substring inside a string with separator

novinosrin — Fri, 05 Jun 2020 16:10:09 GMT

could you please explain call scan(str, 5, _p, _l,'/'); ?

Basically you mentioned in your original post " I would like to extract the string between the 4th folder and the program name". This is the starting point to think through the logic. Given the start being obvious i.e. we begin from the position right after the 4th folder and that is 5th substr separated by '/'. We evaluate the position of the start of the 5th folder including from the point at which delimiter '/' begins. This is part 1.

Secondly we evaluate the end of the beginning of the program name using the 2nd call scan to exclude those characters. So the difference between starting position of program name and ending position of 4th folder is what we do using call scan.

Finally, we extract the substring of chars using the length value evaluated above starting from the ending position of the 4th folder. Hope this helps?

Re: extract une substring inside a string with separator

Jagadishkatam — Fri, 05 Jun 2020 16:23:49 GMT

Alternatively with perl regular expression you can try below code

data want;
 set have;
 need=prxchange('s/(.*sbsas)(.*)(sui_q.*)/$2/oi',-1,str);
run;

Re: extract une substring inside a string with separator

Nasser_DRMCP — Mon, 08 Jun 2020 07:42:24 GMT

Thanks for your help and your reactivity

Re: extract une substring inside a string with separator

Nasser_DRMCP — Mon, 08 Jun 2020 07:55:08 GMT

Thanks Jagadishkatam . could you please explain ? thanks in advance

Re: extract une substring inside a string with separator

Jagadishkatam — Mon, 08 Jun 2020 08:06:01 GMT

The perl regular expression works on the basis of meta characters which recognizes the patterns like digits, letters, special characters, so here we are using the

dot which means any character including the special character
* which means recognize the any character including the special character any number of times
sbsas is the word with which you want to end the pattern
() is group, to recognize a particular group pattern
so here we have 3 groups
s/ - substitution
$2 - keep the second group
-1 - recognize the pattern as it occurs 1 or more
o- retain the pattern to all records
i - ignore case

Re: extract une substring inside a string with separator

Nasser_DRMCP — Mon, 08 Jun 2020 08:29:30 GMT

Thanks

I am sorry , but the file name do not always begin with "SUI_Q" it was just examples. it could be INC_ or MON_ or...

sorry, I forgot to specify it.

and is it possible to use this command into a macro variable ?

thanks

Re: extract une substring inside a string with separator

Jagadishkatam — Mon, 08 Jun 2020 09:12:37 GMT

in that case please try the below code


data want;
 set have;
 need=prxchange('s/(.*sbsas)(.*\/)(.*sas)/$2/oi',-1,str);
run;

Re: extract une substring inside a string with separator

Jagadishkatam — Mon, 08 Jun 2020 09:15:51 GMT

Could you please let me know how you want to use it in a macro variable, so i can help you

Re: extract une substring inside a string with separator

Nasser_DRMCP — Mon, 08 Jun 2020 11:34:43 GMT

sorry, in fact I can get the result in a macro variable by using call symput.

Sorry but there is someting left I don t understand.

why, the second group should be (.*\/) to obtain /SUIVIS/ACCEPTATION/

many thanks